Hydraulic shock absorber



June 24, 1930. Y A. R. McGoNEGAL l1,765,930

HYDRAULIC SHOCK ABSORBER Filed sept. s. 192e 2 smuns--shmn 1 June 24, 1930. A. R. McGoNEGAL 1,765,930

HYDRAULIC ,snocx Asonsa Filed Sept. 8. 1928 2 Smets-sheet 2 V//Lini systems. n y Y A stream of water flowing through a line Patented lune 2d', .lflA

-f'iiai'rafn stares fueses@ .ALFRED ivi'cGONEm/in,k or" onniannnomfvineinin, 'Assienonfro snvnivsnienrriisjl' To; siiivionnn.l MARSH, on Los ANGELES, CALIFORNIA `rHYDRAULIC SHOCK AB'soRBER water hammer which is produced by sudv 5rdenly stopping the flow-ofwater or otherA a fluid passing through the'pipe systems.

lThis application is'a continuation in part *of'my yapplication Serial No.'v l59,434,' filed January 6, 1927, Shock absorbers-for water of pipe has energy in'which quantity and weight of water, velocity and time are ele- -ments If the flow of water is suddenly' cut ,15 offr and the lflow stopped, this 'energy rmust be dissipated and4 itusuallyI takes the form of a thrust or impact on; the end of thepipe at thefpoint of stoppage and causesy through 'molecular movement' the' generation of va zu wave of ldensity which rvpasses-back `through the water pipe-toward thesource of vsupply gradually dying kout in intensity. Its usual reffect is to cause'intense `vibration and move such as fire hosev to transmit" shock to the holder thereof. 'llhisfintensey vibration is V usuallyknown as waterhammer and is objectionable injthat it results in the splitting to eliminate or'dampen out these objectionable v'vibrations thereby insuring that kno "35 hammer in the pipes will take place.

y A kfurther object of `my invention is to provide'avery simple compact and ineX f pensive vdevice for accomplishing these ref sults.

Further objects and advantages ofthe invention will appear as the description proceeds but I desire it to -be understood thaty changes may be made inl theproportions or o hereinafter appended. n i In describing this invention reference will i l be had tothe .accompanying drawings in 'which corresponding parts are similarly numbered throughout the views and inwhich'y dotted lines the deflecting ribs. -1

fied f formV of construction.

Figure-l isa vertical central sectional'view 1 V'of my device, `parts thereofbeing shown; in

Vside elevation.

Fig. 2 isa plan'view Vthereof showing in Fig. 3' is afdiagrainmatic sectional View Y illustrating the Avmode present device. i

Fig. 41s a sectionalview showing a modi- 'of operation of the` Fig; 5 isa 'sectional View showing a fur!y ther modification.

Referring 'more particularlytothe drawi i ings myl shock` absorber consistsvof` a.casing Vor shell generally indicated at A and com-5 prisinganupper shell land a lower shell A l It will thus vbe seen that `by placing'the two margined edges of the shell so that the holes therein align and passing thebo'ltsf thereethroughv the two shells may be securely fastened together as clearly shown in Fig. l.

' ,'I'nteiposedy 'beinveen`V the marginal flanges 3 i .d

lEl() and l of the shellsl and 2 isaspring metal` diaphragm 10 which maybe made of spring 2 which are substantiallydomefshaped and have at the marginal edges thereof flanges 3 and 4 respectively provided with'bolt 'holes 5 through which are extended the bolts 6j provided' at oneend with heads 7 andat the 'other with a screw lthreaded terminal' '8 n y which is adapted to be engaged by a nut 9. ment of thev pipes if they are not fastened 25 securelyin place 0il in the, case of loose pipes,

copper or other suitablemetal and in' Aorder to securely mount the diaphragm l0 between;

the marginal-*flanges 3 and 4 I Aprovide suilt-` l able packingrings il and l2 engaging oppo-f site sides oftliemarginal edge offtl'iediaphragni 10.

This diaphragm 10, as stated :before is of y spring metal so that it is inherently resilient. Thisy inherent resiliency of itself k"normally tends ito maintain the diaphragm l() infa horizontal plane and upon distortiontliereof due to vibrations taking place within the device the diaphragm 10 is adapted to'vibrate Lfreely within the shell and after such vibration ceases plane.v

toreturn to its normal vhorizontal 110. on1one side and .carrying` thereon a stud' p'iperline through the threaded coupling 14E* which communicates directly with the chamthan the stop pin 17 forpurposes which ivill ber 13 and is adapted when' in use to permit the. Ychamber 13'to be completely filled with Water at all times v Depending from the interior Wall of the fshell '1 is a flange 15 providing a recess 16 which is adaptedto `i'eceive'the end of a stop pin'17 therein and it is to'be noted that the `'diameter ofthe recess 16 is slightly vlarger hereinafter be described. l n v v The stoppin 17 is rigidly secured-'to the idiaphragni'l() by means of'anenlarged circularhead 18 bearing against the diaphragm 19 Vand having a screw threaded portion 2O l" Y. 4projecting through an opening 21'in the da? i g phragin-and having in engagement there- VWithV onfthe opposite side of the diaphragm v the Washer 22 which is located in vposition by means of a'nut 23 screw threadedly engaging "thetlireadedportion 20..

Projecting from the screw'threaded porshell 1. Y Y y QAfter'long usage` of Athe present device Aiti '.is'found that the head 1ofwvater actingcoii-V 'staiitly upon the diaphragm 10 tends tou/arp the diaphragm out `Vof its horizontal plane.

i VV the diaphragm'iO constantly in a horin AZontal'*plane I: provide an' adjustment thereenc'ircles the 'stud 19 on the stop pin and at tion 2O is apin kof reduced diameter. which is adapted tofit Within thesoclet 16 in the In order tprevent this Warpage'and mainfor Whichzcomprisesthe'spring 24 which theother end the l'spring 24 bears upon the nut'25V which is provided With a conical or Passing through the shell 2 in airialalign yand thefshell 2 aie suitable packings'29 seen that by adjustmentfof the nut -27 the 'tension ofthe spring 24 is varied in order to takeup' anywarpage ofV this; diaphragm in horizontal position. Y

the diaphragm and therefore maintain It is here to be pointed out vthat the primary'function of r.the spring 24 is not to ,permit the diaphragm 10 to be displaced'by l sition since the inherent resiliency of thediaphragm accomplishes this purpose of itself'.

the impacts and then yreturnr it to normal po- The spring 24: permits yieldingV ofk the dia-- phragml 10 Vbut 'itsprima-ry function iszto talref'up any Warpage occasioned Vbyconstant use so tliatthe -life'of the diaphragm ismate- Vrially increasedV and is `found to be in eflicient" condition after long periods of use.

In the interior of the Vshell 1, and radiating from; Athe"V ldepending flange l provide event it will assume the 111C in Fig. 3. 'Consequently the stop pin'V plurality of verticali ribs 31 ywhich are adapted .to deflect the incoming vibrations Vtoward the diaphragm ythereby* tending to break these vibrations into smaller vibrations Which are absorbed by the diaphragm vibration.` y Y Having novv described in detail the preferred embodiment ofmy invention it will Y be seen that the operation is as follows .The shell A is Ysecured to the end of a pipe line or Wherever they-Waves of vibration are generatedby means of the screw threaded*v connection 14 s o that Wa-ter' at alltimes lls lthe chamber 13 and provides no air space therein; p

Upon stoppage of the flow of stream throiigh the pipeline the'genera-tion offa i Wave or density vis accomplished Which-passes into the chamber 13 and immediatelylsets i up a vibration ofthe diaphragm 10 in unison with the vibrations in the 'stieam,' in this manner absorbingsuch vibrations and preventing the transmission thereof back through tliepipe 'lineas isnormally the case .and the damaging' effectupon the pipes Wil-ly be eliminated together :with the annoying 'Y noise usually present and known as Water*Y hammer.

The resilient spring metal diaphragm is usually made manyjtimes larger in area than the area of itsiiiletjand a satisfactory pro' vportion has been found to be .785 square inch to 33. 18,3 square inches, but of course it is to be understood that various gauge'diafpliragms may be emplo-1edv and various ten-v sion springs may be substituted for the "spring'24 depending uponthe;condition s of i use and the amount of flow fand the volume f ofwater being treated. Y

Upon entering the chamber 13 tions yContact Vwith the vertical ribs 31 and in turn reflects at the fcoinplemeiits. ofthe the vine@ are consequently reflected against the diaf Y phragm at constantly lvarying angles Which "i angles of incidence With the result that the`V i y 'fromthe chamber 13 lback into the supply pipe in any Well defined Waves of density.

,It has hereinbefore been stated thatV the recess 1G receiving tliestop pin isV slightly larger in diameter than the stop pin. `This has beenfound to be essentialv due tothe fact that the diaphragm has been found to i' vibrateunequally under certain conditions and as indicated in Fig. 3 the diaphragm 10 on one side vof thestop pin 17 might'be rei 'iio Y lines of vibrationcross and reci-oss and distort eacn other and so prevent the escapa'ge .f

acting to the impulsev and would assume Vthel position as indicated at B in Fig. 3-While the diaphragm on the opposite side of the stop pin 17 might be under the influence of an impact in theoppos'ite direction inwliichV must assume an angular .position With referfy position'asindicate'd I igveaeeox ence to the vertical to accommodate thisaction@ of the diaphragm and'unless the recess -16 is vslightly in excess yof the diameter of the stop pin 17 suchaction Wouldnot beperf mitted. v

In the' reverse manner. the diaphragm might assume'the positionas indicatedV by the line D, Fig. but in AAany'eveiitthe "enlargement of the recess ltpermits` such movementto take lace. t. v

Due tothe fact t at the diaphragm 1 0 is inherently resilient it Willbe seen that each part ofthe diaphragm takes up the vibra# tions contacting therewithbut inV order to 4'prevent too great a'v vibration of-` the f dia- Y phragm the stop ypin lisprovided which j limits the movement ofthe 'diaphragm but i permits'ample vibration therein Vto damp out all vibrations entering the'chamberlaV Under certain conditions ithasbeen found that ythe diaphragm can bey used Without the necessity 'of any springs "such assp'ringe andflinsuch casean additional stop pin 17 -(Fig. 4) ofthe sameconstruction Vthe pinL 17 projects from the'oppositefside of theV diaphragm and limits themovementin lthat direction On the' other handit hasv been found that spring 242" (Fig. 5) corresponding tospring 24 may beusedl on Vopposite sides of the diaphragm and produceequally goodresults under certain conditions In describingthe Vpresent invention I rel fer to part 2 as constituting shell but I y do not desire lit to 'beunderstood thatlthis shellfQfis of solid construction. If desirable a spider may be substitutedin'placeofthe` shell 2 since itis'not necessary to confine air betweenv the shell 2 y'and thediaphragm7 10 because of the factthat I dofnot rely upon any confined air pocket on one'side of the diaphragm for theV purpose lof permitting displacement of fthe diaphragm thereof to normal position.

y"As a matter of fact' I desireit tofbe distinctlygunderstood .that my invention doesl not operate on ythe principle ofdisplacement' or additionall space for the, surge yor movement of 'the Water but thatmy invention is rbased-upon the principle ofy permitting' the resilient diaphragm'v to vibrate ,inl synch'rof- A nism With the Wavesofdensityginthe` stream fof Water@vv L The inlet 14"isf i llustratedasentering fromthev 'edge Vor laterally of. kthe shell and it krwillA be'readily apparent Athat"theffwaves of pres;

sure, inthe fluid 'streamwilh therefore; travel across the ydiaphragm land 'damped out progressively and resilientlyf; transverse of f the lineV ofv propagation andsince levery min- Y ute portion of the' diaphragm 'acts inreality 'fasbjan independent j diaphragm '-capable of 1 iiexure corresponding lto' the impacty -imping ving thereon, it follows thatthe-"fsur-facesof* 65 the diaphragm maybe said tol independand vreturn which defeats the ently on lthe impulses passing 'across the diaphragm. 'Ihediaphragiml therefore, acts as atympanum and clamps out the vibrations`pro-- gressively, v independently and resilic-intly,`-Y

substantially transverse to the-line of gation of said vibrating impulses.v

Devices ofthe prior art are known wherein the inlet is arranged axially to the vdia-v phragm, butin' such instances the vdiaphragm moves'as a whole to take care of the'k surge',

and -does 'not progressively, independently and resiliently absorb each successivefimf '80 been made-to employ a leather or rubber diaphragm to accomplishV the same '.'res'ult'V butinmost instances a confined air'poclret f has been provided on the opposite 'side of the e diaphragm and thefdiaphragm serves `the Vpurpose ofpreventing contact b etxveenfthe .y prevent absorption of the Water and 'air to air by the Waten In" thesexdevicesof ftheY prior art vitihas been foundfthat inthe course of time the diaphragms lose'theirA resiliency*l and are'V` Warped to such an extent that lthey fail `in* f operation.

In addition none of thel prior'ar-t devices..

of WhichI am aware Vemploy any meansv such as my stop pin 17 lto prevent'too much e flexing ofthe diaphragm. .In the absence Yof some. means onfthefdiaphragm. to prevent excessive warping thereof it has been found that these diaphragx'nsfwill blov7 outorbrealv due to `thepressure of water against l:onefside ofthe'diaphragm Y {In other devices of the priorartrorr'ugated lcylinders or diaphragme have been-y employed vvhichy are' adapted to be.displaced v by the Wavesy of density fin-order to furnishfadditional space kfor thevibration.

It has been found that v'the use'V of {cor`- rugated diaphragms or cylinders is o bjec r` tionable in that in time the consta'nt'pressure of the Water thereagainstftend's to flattenout .the corrugations thereby permitting abiilge e ofthe diaphragm or cylindricallmember and are designed.

purpose forfjvliicli they metal employed inthe diaphragm is YWi 1I havel'd scribed my invention as.' being g used in connection'with' Water' systenis,"but If -I desire it' to be understood that it "is equally' applicable to oil pumping systems or other hier mer or the'like in Huid systems comprising dueetlng vlbratory fluid pressure impulses into e chamber and progressively and independently damping out said vibrations Within the chamber by a movement substantially transversely ofthe line of propagation. p

13. The method of damping outk successive Waves of density in a closed luidfpressure systempoonsisting of progressively and resiliently opposing said Waves 1n a directlon substantially transverselyA v`tov the Aline ofA propagation thereof.

In testimony whereof I have hereunto set ALFRED R. ltfieerroiveGAL.vv

my hand. 

